Comparative studies were carried out on the Al- phthalocyanine and Zn-phthalocyanine uptake in iliac artery wall of rabbit, through transadventitial fluorescence measurements. Two 3.5 Kg Norfolk make rabbit were used. The iliac artery was dissected, isolated and clamped at two points, 1.5 cm apart. The experiment comprised three steps, collecting fluorescence spectra at several point inside and outside of the clamped region of the artery. The excitation source was a 488 nm Argon Laser. Firstly, it was measured the pre and post clamping transadventitial fluorescence without the photosensitizer. After that, 50 (mu) L of AlPc or ZnPc solutions in Cremiphor EL, 2.5 (mu) M, were injected locally into the artery clamped region of each rabbit and fluorescence spectra were collected at t equals 0 and 15 min. Finally, elapsed 30 min. Temporal evolution of the drug uptake by the artery wall was studied analyzing the intensities of the fluorescence peaks at 682 and 678 nm for AlPc and ZnPc, respectively. It was found that AlPc is more absorbed and remains for a longer time in the iliac artery wall than the ZnPc.